89 lines
2.1 KiB
C
89 lines
2.1 KiB
C
/**
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* Maxim ADC has not so suitable default settings after startup.
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* So we will create init function to tune this ADC.
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*/
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#include <stdlib.h>
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#include "ch.h"
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#include "hal.h"
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#include "max1236.h"
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// Data buffers
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static i2cblock_t max1236_rx_data[MAX1236_RX_DEPTH];
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static i2cblock_t max1236_tx_data[MAX1236_TX_DEPTH];
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// ADC results
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static uint16_t ch1 = 0, ch2 = 0, ch3 = 0, ch4 = 0;
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/* Error trap */
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static void i2c_max1236_error_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
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(void)i2cscfg;
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int status = 0;
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status = i2cp->id_i2c->SR1;
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while(TRUE);
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}
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/* This callback raise up when transfer finished */
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static void i2c_max1236_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
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(void)*i2cp;
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/* get ADC data */
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ch1 = ((i2cscfg->rxbuf[0] & 0xF) << 8) + i2cscfg->rxbuf[1];
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ch2 = ((i2cscfg->rxbuf[2] & 0xF) << 8) + i2cscfg->rxbuf[3];
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ch3 = ((i2cscfg->rxbuf[4] & 0xF) << 8) + i2cscfg->rxbuf[5];
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ch4 = ((i2cscfg->rxbuf[6] & 0xF) << 8) + i2cscfg->rxbuf[7];
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}
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// ADC maxim MAX1236 config
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static I2CSlaveConfig max1236 = {
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NULL,
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i2c_max1236_error_cb,
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0,
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0,
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max1236_rx_data,
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max1236_tx_data,
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0b0110100,
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7,
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0,
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0,
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{NULL},
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};
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/**
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* Initilization routine. See datasheet on page 13 to understand
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* how to initialize ADC.
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*/
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void init_max1236(void){
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/* this data we must send via IC to setup ADC */
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max1236.rxbytes = 0;
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max1236.txbytes = 2; // total 2 bytes to be sent
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max1236.txbuf[0] = 0b10000011; // config register content. Consult datasheet
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max1236.txbuf[1] = 0b00000111; // config register content. Consult datasheet
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// transmit out 2 bytes
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i2cAcquireBus(&I2CD2);
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i2cMasterTransmit(&I2CD2, &max1236);
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while(I2CD2.id_state != I2C_READY){
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chThdSleepMilliseconds(1);
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}
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/* now add pointer to callback function */
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max1236.id_callback = i2c_max1236_cb;
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i2cReleaseBus(&I2CD2);
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}
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/* Now simply read 8 bytes to get all 4 ADC channels */
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void read_max1236(void){
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max1236.txbytes = 0;
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max1236.rxbytes = 8;
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i2cAcquireBus(&I2CD2);
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i2cMasterReceive(&I2CD2, &max1236);
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i2cReleaseBus(&I2CD2);
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}
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